Unexpected removal of storage cart

I started my single player world on the southern border of the eastern kingdom. I eventually needed to travel north to locate iron, so I built a storage cart, with chests, crate, stockpiles, etc; but I also placed a bed, crafting table and a couple other things, just to be prepared up there. Once I arrived in the area I needed, I parked said cart, and placed a couple stairs at either end to stop it rolling away. After that I proceeded to mine and expand on the area, running up and down a mountain side to an iron vein, chasing deer around the area, etc. I then made a return trip to my starting point to gather some things left behind. I left the cart as it was, pinned between stairs and holding my spawn bed. I made the trip, at least 3 map blocks south, grabbed my supplies, and fast traveled back to my cart area. All of that went smoothly, no issues.

But then I began my first Windmill/Sawmill building in that area, planted some crops for later resources I would need, and some extra trees around the place. When I began to run out, I went a few hundred feet away to harvest a bit, when I run back after less than 5 minutes, my entire cart has just disappeared. I'm not positive why this would happen then, and not when I fully left the area earlier, but I found it odd (and mildly frustrating, as it still held most of my excess supplies). I do understand that with a few workshop mods running (just a sleep thru the night, and character animation libraries to support that), the blame is not solely on the game. Just thought I would submit the report.

Thank you for the amazing games, and your time here.

P.S. I'm not sure if there is a game log file I could/should upload. It didn't crash or anything. If needed I could find it with some assistance.